2.0版本中，对象extend属性没有生效
服务版本： "@steedos/service-meteor-package-loader": "^2.0.9", "@steedos/service-mongodb-server": "2.0.9", "@steedos/service-package-loader": "2.0.9", "@steedos/service-metadata-server": "2.0.9", "@steedos/service-steedos-server": "^2.0.9",
